Roller blinds are used in a variety of ways in motor vehicles and/or in other application areas. For example, roller blinds are used in vehicles to secure baggage, as a screen, as a sunshade or the like. Roller blinds comprise, in principle, a tubular winding shaft on which a flexible sheet-like structure, for example a canvas or a netting material, is fastened such that it can be wound up and unwound.
In order to produce a roller blind, it is usually the case that first all the desired size of flexible sheet-like structure or roller-blind web is cut out of the desired material. The roller-blind web is usually cut such that lateral tabs, which project beyond lateral peripheries determining the width of the roller-blind web, remain at a rear end of the roller-blind web, by which the roller-blind web is fastened on the winding shaft. The tabs give rise, for example, to a T-shaped roller-blind web. For fastening the roller-blind web on the winding shaft, the end of the roller-blind web is adhesively bonded to the winding shaft, the tabs projecting laterally beyond the peripheries being folded over and inserted into the winding shaft from the ends of the latter. The act of inserting the tabs into the interior of the tubular winding shaft allows good, secure fastening. In order to form such tabs, however, it is first of all necessary to provide a material with a width which corresponds to the width of the roller-blind web plus the width of the two lateral tabs. With the exception of the tabs, the excess material is removed, in a further step, from the lateral peripheries of the roller-blind web. Production of such a roller blind thus results in a lot of material of the sheet-like structure being wasted.
It is an object of the invention to provide a method of fastening a flexible sheet-like structure on a winding shaft in which waste is reduced. It is a further object of the invention to provide a corresponding roller blind.
This object is achieved by a method of fastening a flexible sheet-like structure, in particular a canvas, on a tubular, in particular hollow-cylindrical, winding shaft, comprising the following steps: introducing, in a circumference of the tubular winding shaft, at least one aperture which passes through a wall of the winding shaft, a width of the aperture being greater than a thickness of the flexible sheet-like structure; producing an angleable tab on the flexible sheet-like structure, and inserting the angled tab into the at least one aperture on the winding shaft. The flexible sheet-like structure is usually rectangular with a longitudinal direction along which it can be wound up and unwound, also referred to as the winding-up direction, and a transverse direction. The width of the flexible sheet-like structure, i.e. the extent in the transverse direction, is usually essentially equal to the length of the winding shaft in its axial direction, it being possible for the winding shaft to project beyond the flexible sheet-like structure in the axial direction of the winding shaft for better handling. Introduction according to the invention of apertures on the circumference of the winding shaft makes it possible to insert tabs at a location other than the open ends of the winding shaft, for fastening in the winding shaft. The sheet-like structure has preferably already been cut to a normal size which is appropriate for the function of the roller blind. The sheet-like structure may additionally be adhesively bonded to the winding shaft. Fitting by means of tabs can prevent rotation and/or displacement of the canvas relative to the winding shaft even if additional adhesive bonding should fail and/or if there is no additional adhesive bonding provided. The tab can be produced at a corner of the flexible sheet-like structure by folding.
In a further configuration, the flexible sheet-like structure is fixed on the winding shaft by a bushing, in particular a bearing bushing, which can be inserted into the end of the winding shaft. An inserted bushing can cover the tab inserted into the winding shaft, in which case the bushing clamps the tab firmly in place on an inner wall of the winding shaft. In one embodiment, the bushing is a bearing bushing and thus serves for bearing the winding shaft and for fastening the flexible sheet-like structure on the winding shaft. Instead of the bearing bushing, however, it is also possible to use a latching bushing, in which case a separate element serves for bearing the shaft.
In a further configuration, the tab is produced by cutting into- a flexible sheet-like structure and/or by deformation at a lateral periphery and/or an end edge of the flexible sheet-like structure. The sheet-like structure has preferably already been cut to a normal size which is appropriate for the function of the roller blind. According to the invention, the cutting or angling operation for forming the tab give rise to only minimal waste, if any at all. In other configurations, however, it may be advantageous if the tab projects longitudinally and/or transversely beyond the normal, functionally appropriate size of a roller-blind web. Fastening according to the invention likewise makes it possible at least to reduce waste.
In a development of the method, the at least one aperture is designed as a slot in the circumferential direction with an arc length which is smaller than the circumference of the tubular winding shaft, and produced on the flexible sheet-like structure, by a cut in the transverse direction of the flexible sheet-like structure, is at least one tab which corresponds to the slot and has a length which, at most, is equal to the arc length. In a preferred configuration of the invention, the cut in the transverse direction is started at a lateral periphery of the flexible sheet-like structure. One cut can thus produce a tab which can be angled at any desired angle for fastening purposes. If the cut, in contrast, is formed in the sheet-like structure at a distance from a lateral periphery, then deformation of the flexible sheet-like structure which is necessary for angling the tab can be simplified by further cuts.
In one exemplary embodiment, the at least one slot is introduced in the circumferential direction at a distance from one end of the winding shaft, a width of the tab being approximately equal to the distance of the slot from the end of the winding shaft. It is possible here for a flexible sheet-like structure, of which the width corresponds to the length of the winding shaft in the axial direction, to be fitted on the winding shaft without any waste. In one configuration, the width of the tab, by an appropriate cut, may also be selected to be greater than the distance of the slot from the end of the winding shaft, the tab not being inserted into the slot on the winding shaft over the entire width. The slot is preferably introduced in the circumferential direction at a distance from the end of the winding shaft which is smaller than a length of a bushing which can be inserted into the end of the winding shaft, the distance corresponding, in particular, approximately to a quarter to three quarters of the length, preferably approximately half the length.
In a development of the method, at least one tab is produced on the flexible sheet-like structure by the first cut in the transverse direction, and a second cut, which crosses the first cut in the longitudinal direction, of the flexible sheet-like structure. The second cut here is preferably introduced from an end edge which can be fastened on the winding shaft. In other configurations, a third cut is introduced in order for a tab which can be angled at right angles to be produced by three cuts arranged in a U-shaped manner.
In a development of the method, the aperture is produced as a cutout which is open toward the end of the winding shaft. Such a cutout allows particularly straightforward insertion of the tab. The arc length of the cutout here should be selected such that the winding shaft is not overly weakened by the cutout.
In a development of the invention, the aperture is produced as an essentially U-shaped and/or V-shaped cutout. A corresponding tab on the sheet-like structure can be produced by one or two slots, it being possible for the tab, for fastening purposes, to be clamped beneath the nose formed by the V-shaped or U-shaped aperture.
In a development of the method, the at least one aperture is introduced into the winding shaft at at least one end as a slot in the axial direction, a tab which corresponds to the slot being produced in the flexible sheet-like structure. In one configuration, the tab is produced by at least one cut in the longitudinal direction of the flexible sheet-like structure. In one configuration of the invention, the cut in the longitudinal direction terminates at the end edge of the flexible sheet-like structure. One cut thus produces a tab which can be angled at any desired angle and can be inserted into a correspondingly oriented slot of the winding shaft. In other configurations, the longitudinal cut is produced at a distance from the edge, this producing an angleable tab which can be pushed, for example, onto a corresponding nose on the winding shaft.
In one embodiment of the method, the flexible sheet-like structure is adhesively bonded to the winding shaft. Adhesive bonding here can take place both on the tabs and in regions between the tabs.
In a development of the method, the bushing has a latching nose which, when the bushing is pushed into the winding shaft, is pushed over the tab inserted into the aperture.
The object is also achieved by a roller blind, in particular a roller blind for fitting in a motor vehicle, comprising a tubular winding shaft and a sheet-like structure which is fastened thereon such that it can be wound up and unwound, wherein the winding shaft has at least one aperture which penetrates a wall and has a width which is greater than a thickness of the flexible sheet-like structure, and the flexible sheet-like structure has at least one angleable tab which, for connection of the flexible sheet-like structure to the winding shaft, is inserted into the interior of the winding shaft via the aperture. Insertion of the sheet-like structure into the winding shaft allows the sheet-like structure to be fastened on the winding shaft in the interior of the latter, for example to be adhesively bonded and/or clamped to the same, preferably by way of a bushing.
Further advantages of the invention can be gathered from the following description of exemplary embodiments of the invention which are illustrated schematically in the drawings. The same or similar components are indicated in the drawings by like designations. All the features and/or advantages, including design details, spatial arrangements and method steps, which can be gathered from the claims, the description or the drawings may be essential to the invention both on their own and in a wide variety of different combinations. Features which are illustrated or described as part of an exemplary embodiment can likewise be used in another exemplary embodiment in order to obtain a further embodiment of the invention.